Convert global 'this' references to 'global' before transpiling (#25)

* When transpiling, run a custom babel plugin which turns global 'this' references into 'global' references.

* Add unit test to verify global this becomes 'global' and not 'undefined'

lib/global-this.js

@@ -0,0 +1,24 @@
+'use strict';
+
+const THIS_BREAK_KEYS = [ 'FunctionExpression', 'FunctionDeclaration', 'ClassProperty',
+	'ClassMethod', 'ObjectMethod' ];
+
+// Walk the AST looking for 'this' references intended to be references to global
+// Replace them with an explicit 'global' reference
+module.exports = function (_ref) {
+	const t = _ref.types;
+	return {
+		visitor: {
+			ThisExpression(path, state) {
+				if (
+					state.opts.allowTopLevelThis !== true
+					&& !path.findParent((path) => !path.is('shadow')
+					&& THIS_BREAK_KEYS.indexOf(path.type) >= 0)
+				) {
+					// TODO: Spit out a warning/deprecation notice?
+					path.replaceWith(t.identifier('global'));
+				}
+			}
+		}
+	};
+};

lib/jsanalyze.js

@@ -76,7 +76,7 @@ function getMemberValue(node) {
 function getTitaniumExpression(member) {
 	var value = getMemberValue(member),
 		tiNodeRegExp = /^Ti(tanium)?/;
-	if (value == null) return null;
+	if (value == null) { return null; }
 	if (tiNodeRegExp.test(value)) {
 		// if value.startsWith('Ti.'), replace with 'Titanium.'
 		if (value.indexOf('Ti.') === 0) {
@@ -123,7 +123,7 @@ exports.analyzeJs = function analyzeJs(contents, opts) {
 			contents = contents.split('\n');
 			if (ex.line && ex.line <= contents.length) {
 				errmsg.push('');
-				errmsg.push('    ' + contents[ex.line-1].replace(/\t/g, ' '));
+				errmsg.push('    ' + contents[ex.line - 1].replace(/\t/g, ' '));
 				if (ex.col) {
 					var i = 0,
 						len = ex.col,
@@ -142,7 +142,7 @@ exports.analyzeJs = function analyzeJs(contents, opts) {
 	// find all of the titanium symbols
 	traverse(ast, {
 		MemberExpression: {
-			enter: function(path) {
+			enter: function (path) {
 				var memberExpr = getTitaniumExpression(path.node);
 				if (memberExpr) {
 					symbols[memberExpr.substring(9)] = 1; // Drop leading 'Titanium.'
@@ -170,6 +170,7 @@ exports.analyzeJs = function analyzeJs(contents, opts) {
 
 	// transpile
 	if (opts.transpile) {
+		options.plugins.push(require.resolve('./global-this'));
 		options.presets.push([ env, { targets: opts.targets } ]);
 	}
 
@@ -246,7 +247,7 @@ exports.analyzeHtml = function analyzeHtml(contents, relPath) {
 	}
 
 	try {
-		var dom = new DOMParser({ errorHandler: function(){} }).parseFromString('<temp>\n' + contents + '\n</temp>', 'text/html'),
+		var dom = new DOMParser({ errorHandler: function () {} }).parseFromString('<temp>\n' + contents + '\n</temp>', 'text/html'),
 			doc = dom && dom.documentElement,
 			scripts = doc && doc.getElementsByTagName('script'),
 			i, len, src, m, p, q, r;

package.json

@@ -6,7 +6,7 @@
 		"titanium",
 		"mobile"
 	],
-	"version": "0.4.8",
+	"version": "0.4.9",
 	"author": {
 		"name": "Appcelerator, Inc.",
 		"email": "[email protected]"
@@ -53,6 +53,6 @@
 		"node": ">=0.6.6"
 	},
 	"scripts": {
-		"test": "JUNIT_REPORT_PATH=junit_report.xml mocha --require tests/init --reporter mocha-jenkins-reporter --check-leaks tests/test-tiappxml.js"
+		"test": "JUNIT_REPORT_PATH=junit_report.xml mocha --require tests/init --reporter mocha-jenkins-reporter --check-leaks tests/*_test.js"
 	}
 }

tests/init.js

@@ -1,9 +1,10 @@
-global.should = null;
-global.should = require('should');
-
-var util = require('util');
-global.dump = function () {
-	for (var i = 0; i < arguments.length; i++) {
-		console.error(util.inspect(arguments[i], false, null, true));
-	}
-};
+'use strict';
+global.should = null;
+global.should = require('should');
+
+var util = require('util');
+global.dump = function () {
+	for (var i = 0; i < arguments.length; i++) {
+		console.error(util.inspect(arguments[i], false, null, true));
+	}
+};

tests/jsanalyze_test.js

@@ -0,0 +1,10 @@
+'use strict';
+
+const jsanalyze = require('../lib/jsanalyze');
+
+describe('jsanalyze', function () {
+	it('#analyzeJs() converts global "this" references into "global" references when transpiling', function () {
+		const results = jsanalyze.analyzeJs('this.myGlobalMethod = function() {};', { transpile: true });
+		results.contents.should.eql('"use strict";global.myGlobalMethod = function () {};');
+	});
+});

tests/run.js

@@ -1,17 +1,21 @@
-var spawn = require('child_process').spawn,
-	exitCode = 0,
+'use strict';
+
+const spawn = require('child_process').spawn, // eslint-disable-line security/detect-child-process
 	tests = [
-		'test-tiappxml.js'
+		'jsanalyze_test.js',
+		'tiappxml_test.js'
 	];
 
+let exitCode = 0;
+
 (function next() {
 	if (tests.length === 0) {
 		process.exit(exitCode);
 	}
-	
+
 	var file = tests.shift();
 	console.log(file);
-	
+
 	var proc = spawn('node', [ 'tests/' + file ]);
 	proc.stdout.pipe(process.stdout);
 	proc.stderr.pipe(process.stderr);